Electric switch



Nov. 21, 1950 J. w. LAWSON ETAL 2,531,377

ELECTRIC SWITCH Original Filed July 22, 1948 4 Sheets-Sheet 1 INVENTORSJam 11. Mwsw/ 4 N 1950 J. w. LAWSON ETAL 2,531,377

ELECTRIC SWITCH Original Filed July 22, 1948 4 Sheets-Sheet 2 INVENTORSJOHNM LJWSON 4,, y h/I L M M E. BRouw o M, (um, wwm

Nov. 21,1950 J; w. LAWSON ETAL 2,531,377

ELECTRIC swncn Original Filed July 22, 1948 4 Sheets-Sheet; 5

INVENTORS JOHN M LAMSOA! 4* y WILLIAM 5.. anon Nov. 21, 1950 J. w.LAWSON EI'AL 2,531,377

ELECTRIC swrrcu Original Filed July 22, 1948 4 Sheets-Sheet 4' INVENTORSJohw MLAh/SON 4 BY LL MM E, gnaw Patented Nov. 21, 1950 ELECTRIC SWITCHJohn W. Lawson and William E. Brown, Anderson, Ind., assignors toGeneral Motors Corporation, Detroit, Mich., a corporation of DelawareOriginal application July 22, 1948, Serial No. 40,196. Divided and thisapplication July 19, 1949, Serial No. 107,357

3 Claims. (Cl. 20016) This invention relates to systems of direction andstop signalling for automotive use.

This application is a division of application Serial No. 40,1 96filedJuly 22, 1948.

An object of the invention is to provide a turn signal switch of simpleeconomical and durable construction by which current is directed to thesignal lamps which indicate direction of turn and stopping when brakesare applied. This object is accomplished in the disclosed em bodiment ofthe invention by the provision of two rows of stationary contacts ofthree contacts each. The center contact of the first row is connectedwith the current source through a stop switch which is closed when thebrakes are applied and the end contacts of the first row are connectedrespectively with right-rear and left-rear lamps. The center contact ofthe second row is connected with the source through a flasher and theend contacts of the second row are connected respectively with theright-front and left-front turn-signal lamps. The switch provides threemovable contacts which are simultaneously actuated. One of the movablecontacts has a center position connecting all contacts of the first rowand has pos'tions on either side of center position for connecting thecenter contact of the first row with one or the other of the endcontacts of the first row. Thus the stop light switch will cause both ofthe rear lamps to burn in case the turn signal switch is in no-turn orneutral status, and will cause one or the other of the rear lamps toburn steadily in case the turn signal switch is manipulated to indicateaturn. When the turn signal switch is manipulated to indicate a rightturn, another movable contact connects the stationary center contact ofthe second row with those end contacts of the two rows which areconnected respectively with right front and right rear lamps which burnintermittently.

When the turn signal switch is manipulated to indicate a left turn,another movable contact connects the stationary second contact of thesecond row with those end contacts of the two rows which are connectedrespectively with the left-front and left-rear lamps which burnintermittently.

. The first mentioned movable contact has five contact bosses. Thenon-conducting stationary contact support provides recesses around thecontacts of the first row so that the nonfunctioning contact bosses ofthe first mentioned movable contact will not en age a stationary partand will not therefore, interfere with proper engagement with stationarycontacts by the functioning contact bosses. The first mentioned movablecontact makes either three-point (tripod) or twopoint engagement withstationary contacts. Each of the other movable contacts has threecontact bosses and can make by virtue of threepoint contact the properelectrical connection with three stationary contacts.

Another object is to facilitate the control of pilot lamps whichindicate the functioning of the system. For this purpose, each endcontact of the second mentioned row of fixed contacts is connected alsowith a pilot lamp. The two pilot lamps are connected with the currentsource by a relay switch associated with the flasher. When manipulatedto indicate a turn, the turn-signal switch shorts out one of the pilotlamps while the other pilot lamp burns, its circuit being made throughthat front turnsignal lamp which is not then in circuit with theflasher.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein a preferred embodiment of the invention is clearlyshown.

In the drawings:

Fig. 1 is a wiring diagram of a directional signal light and stop lightsystem embodying the present invention.

Figs. 2 and 3 show the system under different operating conditions.

Fig. 4 is a bottom view of a switch included in the system shown in Fig.1.

Fig. 5 is a view in the direction of arrow 5 of Fig. 4, certain partsbeing shown in section.

Fig. 6 shows the switch case in section on line 6-6 of Fig. 5 and abottom plan view of the movable contacts of the switch.

Fig. 7 is a sectional view on line 'l'| of Figs. 4, 5, 6 and 9.

Fig. 8 is a sectional view on line 8-8 of Figs. 4 and 6.

Fig. 9 shows a top plan view of the carrier of the movable contacts ofthe switch, the case being in section on line 99 of Fig. 5.

Fig. 10 is a plan view of a switch housing and switch operatingmechanism.

Fig. 11 is a fragmentary view similar to Fig. 10, certain parts beingremoved in order to show the switch case in position in the housing.

Figs. 12 and 13 are sectional views on lines l2-l2 and l3l3 respectivelyof Fig. 10.

Figs. l4, l5 and 16 are inside views of the switch back plate 26 withthe movable contacts shown in difierent positions in these views;

The switch case is shaped me an 'arcuate channel and is provided withmounting brackets 2| and 22. Its concentric cylindrical side walls 23and 24 merge with an arcuate, flat wall 25. As shown in Fig. 11, wall 25is the top wall. The case 20 is closed at the bottom (top in Fig. 4) bya non-conducting back plate 26 having notches 21 for receiving tangsextending from the side walls of the case, said tangs being bent over at28 into recess 29 provided by the plate. The plate carries members 30,3|, 32, 33, 34' and 35 which serve as terminals and also as stationarycontact members, said members being inserts (as shown in Fig. 8) inplate 26 which is made of molded insulating material. Case 20 encloses amovable contact carrier 31 of arcuate shape as shown in Fig. 6 which ismovable in an arcuate path between the case walls 23 and 24 and isguided for such movement by a plurality of balls 38 receivedrespectively by recesses 39 of the carrier 31 and bearing againstthecorner portions of the case 26. Contact springs 49 which urge movablecontacts I0, 18 and 80 (Fig. 6) toward the plate 26 maintain the carrier31 in contact with balls 38 and the latter in contact with the walls ofthe switch case as shown in Fig. 7.

Carrier 31 provides a cylindrical lug 4| which extends through anarcuate slot 42 of case wall 25 and through a radial slot 43 of a ringplate 44 supported by housing 65 for rotation coaxially thereof. Housing45'is adapted to be mounted upon the stationary steering column post ofan automobile and to be located'under the steering wheel so that ahandle 46 attached to the plate 44' is readily accessible to the driver.Housing 45 is provided with tracks 41 for receiving balls which arereceived by tracks provided by clips 49 and 50 attached to the plate 44,clip 49 being relativel rigid and clip 56 relatively resilient. Plate 44is retained in neutral position shown in Fig. 10 by the cooperation of adetent clip'EiI attached to housing 45 with a roller 52 and a stud 53pivota-lly attached to plate 44'. Switch case bracket 2| is attached bya screw 2Ia to housing 45 and switch case bracket 22 is attached by ascrew 22a. Bracket 22 provides pivots 55 for arms 56 carrying studs 56supporting rollers 5'. which extend through arcuate slots 53 in plate44. The ends of the studs 56 extend above the plate l -l and are groovedat 56a (Fig. 13), to receive the hooked ends of a spring 59. There isslight clearance between the sides of the slots 58 and the rollers 61.The function of the spring 59 tends to urge the pivots of these rollerstoward each other and to bias them toward the ends of a lever 69 pivotally supported by a stud 6|. When handle 46 is moved down in Fig. 10to rotate plate 44 clockwise. the surface 60a of lever 60 is broughtinto contact with the upper roller 51 which biases the lever 60 toward acam rotating with the steering wheel shaft (not shown). Similarly whenhandle 46 is moved up and plate 44 is moved counterclockwise, theportion 66b of lever 69 is engaged by the lower roller 51, therebybiasing it toward the steering wheel cam.

In advance of making a right turn, the handle 46 is moved down to causelever 63 to be urged clockwise so that its upper portion will be engagedby a cam rotatable with the steering wheel shaft. Consequently when thesteering wheel is turned clockwise to make a right turn, the tendency isto maintain the plate 44 in the position in which it hadbeen moved bythe handle 46. After the turn l asbeen partially completed and thedriver reverses motion, of ,.the. steering, wheel. to straighten out thefront wheels, of the automo bile, this reverse motion of the steeringwheel through mechanical connection with the end of lever 60 causesplate 44 to move back to neutral position, thereby interrupting thesignal for the right-hand turn. The same thing happens with respect tothe left-hand turn. The mechanism for accomplishing this is not per se apart of the present invention.

Referring again to Figs. 4 to 8, the contact carrier 31 supports amovable contact 10 having five contact bosses 1|, I2, 13, 14, 15, acontact 16 having bosses 11, 18 and 19 and a contact having bosses 8|,82 and 83. Between the carrier 31 and each of the bosses of the contacts16 and 80 there is located a spring 40 as shown in Fig. 7. Between thecarrier 31 and each of the bosses 1|, 13 and 15 there is located aspring 40 as shown in Fig. 8.

Fig. 1 shows the movable contacts 16 and in neutral position. Contacts30 and 32 are not connected with the contact 3|. Contact 10 connectscontacts 33, 34 and 35. When the stop light switch 90 is closed, currentflows from the battery 9| to the right rear lamp 92 and the left rearlamp 93 to indicate application of brakes.

When lever 46 (Fig. 10) is moved counterclockwise the contacts 10, 16and 80 move to the position shown in Fig. 2. Current then flows frombattery 9| to flasher terminal 94, hinged blade 95, hot wire 96,resistor 91, contact 98 (normally separated from contact 99 carried byblade magnet coil I00, terminal IOI, wire I02, contact 3|, contact 89,contact 30, wire I03, lamp I94 and also through contact 80, contact 33and wire I05 to left rear lamp 93. Current flowing in wire 96 causes itto expand to permit blade 95 to bias downwardly to move its contact 99into engagement with contact 98, thereby short-circuiting resistor 91and hot Wire 96. The temperature of wire 96 decreases and it contractsto pull contact 99 away from contact 99, thereby interrupting theshort-circuit of wires 96 and 91 whereupon current again flows to heatwire 96 and contact 99 returns into engagement with contact 98. Thiscycle is repeated so long as contact 80 remains in the position shown.Therefore the lamps I04 and 93 burn intermittently to indicate by aflashing signal a left turn. At the same time a hinged armature bladeI06 is attracted to move its contact I01 into engagement with a contactI98. This connects the battery with left turn pilot lamp I09 and rightturn pilot lamp IIO. Lamp I09 burns because its circuit is completedthrough right front lamp II I which does not burn perceptibly becausethe voltage drop through it is insufficient. If the brakes are applied,switch 90 is closed and lamp 92 burns steadily to indicate a stop, whilelamp 93 burns intermittently to indicate a turn.

Fig. 3 shows the positions of the switch contacts 10, 16 and 80 whenhandle 46 has been moved down (Fig. 10) to indicate a right turn. Sincecontact 16 connects contacts 3|, 32 and 35, right front signal lamp I Iand right rear signal lamp 92 burn intermittently through the operationof the flasher in the manner described with reference to Fig. 2. Blade I06 moves up as before to connect contacts I01 and I08 and pilot lamp 0indicates that the flasher is operating the right turn signals, thecircuit of lamp IIO being completed through lamp I04 which does not burnperceptibly. Pilot lamp I09 does not burn since it is short-circuited bythe circuit through magnet coil I00 andwire I02. When brakes are appliedstopflight switch 90 is closed and left rear lamp 93 burns steadily toindicate the application of brakes while lamp 92 is flashing to indicatea right turn.

From the foregoing it is apparent that the system provides for theindication of turns by the flashing of the proper front and rear lamps,for the steady burning of the non-flashin rear lamp when brakes areapplied and for the indication by pilot lamps that the system isoperating properly for left and right turns. If, when the system is setfor indicating a left turn, pilot lamp I09 does not burn, this is anindication that the signal system is not operating properly; and, whenright turn pilot lamp H9 does not burn when the switch is set for rightturn signal, this is an indication that the system is not operatingproperly.

Referring to Figs. 14, 15 and 16, it will be noted that the switch backplate 26 is provided with recess d adjoining the heads of contactmembers 33, 34 and 35. In the neutral position of the switch, bosses H,73 and 15 engage contacts 33, 34 and 35, respectively, and bosses l2 andI4 face into the recess (1 and do not touch anything. Since bosses H, 13and 15 are not on the same line, they make a tripod or three-pointcontact with contacts 33, 34 and 35. In other positions of contact Illas shown in Figs. 15 and 16, a two-point contact is made with stationarycontacts. The other movable contacts have three bosses each so that theywill make a tripod or three-point contact respectively with contacts 3I, 32, 35 and contacts 30, 3|, 33. Although contact has five bosses, notmore than three of said bosses will engage a stationary part at the sametime.

While the embodiment of the present invention as herein disclosed,constitutes a; preferred form, it is to be understood that other formsmight be adopted, all coming within the scope of the claims whichfollow.

What is claimed is as follows:

1. A switch comprising a case, a non-conducting cover for the case, sixstationary contacts supported by the cover and arranged in first andsecond rows of three contacts each, a contact carrier guided by the casefor movement from an intermediate position to either of two endpositions, two L-shaped movable contacts movable with the carrier andeach having three contact bosses respectivel for engaging an end contactof the first row, an end contact of the second row and the intermediatecontact of the second row, one of the L-shaped contacts bridging saidstationary contacts in one end position of the carrier, while the otherL-shaped contact engages the cover and vice versa, spring means movablewith the carrier for urging the L-shaped contacts toward the carrier sothat each makes three-point engagement with said stationary contacts orwith the cover, and a third movable contact of triangular formationmovable with the carrier and providing five contact bosses arranged inconverging rows, one row comprising bosses I, 2 and 3, and the other rowcomprising bosses 3, 4 and 5, said bosses I, 3 and 5 respectivelyengaging the first row of stationary contacts in the intermediateposition of the carrier and said bosses 2 and 4 respectively engagingintermediate and end contacts of the first row of stationary contacts inthe end positions of the carrier, said carrier being provided withrecesses adjacent the contacts of the first row of stationary contactsfor receiving only the bosses of the triangular movable contact which donot engage said stationary contacts, and spring means movable with thecarrier for urging the triangular contact toward the cover, said lastnamed contact having, by virtue of said recesses no greater than threepoint engagement with fixed contacts and no engagement with the cover.

2. A switch comprising a U-shaped housing having a yoke and side arms,said yoke having an opening, a carrier comprising an elongated body ofnon-conducting material loosely positioned between the arms of thehousing, means for spacing the body from yoke and arms and guiding thebody in parallelism with the arms from a medial position to positions onopposite sides of the medial position, a closure attached to the arms, afirst and second row of stationary contacts supported by the closure,three biased movable contacts carried by the body, two of said contactsbeing formed to provide contact portions capable of engaging twostationary contacts in the first row and a single contact in the secondrow while the third movable contact engages only the contacts in thesecond row and said contact portions being spaced so that when theswitch is in its normal position all of the stationary contacts of thesecond row will be bridged by the third movable contact, and when thebody is moved to one side of the normal position one of said contactscapable of engaging contacts of both rows of stationary contacts willbridge two contacts of the first row and one contact of the second rowwhile the second contact of the same type will engage only one contactof the first row and vice versa, and said third contact will engage twocontacts of the second row.

3. A switch comprising an open sided housing, means closing the openside of the housing, a plurality of rows of spaced stationary contactsinsulatingly supported by the housing, a movable carrier within thehousing and guided for movement between opposite walls of the housingfrom a medial position to positions on opposite sides of the medialposition, a bridging member carried on opposite sides of the carriereach formed to provide contact portions respectively, capable ofengaging a stationary contact of one row and a pair of stationarycontacts in another row, said end bridging members being spaced so thatin one side position of the carrier one of said end bridging memberswill engage at least three stationary contacts while the other endbridging members engages at least one stationary contact and vice versa,an intermediate bridging member movable with the carrier and providingat least five spaced contact portions arranged so that when the carrieris in its medial position three stationary contacts of one row will bebridged thereby but only two stationary contacts of said one row will bebridged by said intermediate bridging member when the carrier is ineither side position.

JOHN W. LAWSON. WILLIAM E. BROWN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,245,467 Kingsbury Nov. 6, 191'?2,303,693 Hill Dec. 1, 1942

